Touch driving apparatus, touch control apparatus and touch driving method

ABSTRACT

A touch driving apparatus, a touch control apparatus and a touch driving method are provided. The touch driving apparatus includes at least one output module. Each output module comprises at least two output stage circuits, each having an output terminal configured to output a driving signal to a connected driving electrode. The method includes: for each output module, determining a first and a second output stage circuit groups in the current driving time period according to a CDM code matrix. A first driving signal group corresponding to the first output stage circuit group is expected to discharge a first driving electrode group, and a second driving signal group corresponding to the second output stage circuit group is expected to charge a second driving electrode group; and controlling utilizing power from the first driving electrode group to charge the second driving electrode group, in response to the determination.

TECHNICAL FIELD

The present disclosure relates to a field of touch control, and moreparticularly, to a touch driving apparatus, a touch control apparatus,and a touch driving method.

BACKGROUND

In recent years, a touch control apparatus including a so-called touchpanel capable of detecting external approaching objects has attractedattention. For example, the touch panel, for example, is assembled on orintegrated with a display apparatus such as a liquid crystal displayapparatus, an OLED display apparatus, etc., so as to be used as a touchdisplay apparatus with a touch detection function.

The touch panel may be provided with a touch sensor, for example, aprojection capacitive touch sensor. The touch sensor may be implementedas being in a mutual-capacitance or self-capacitance sensing operationmode. In a mutual-capacitance implementation or operation mode, thetouch sensor may include an array of driving and sensing electrodes thatform an array of capacitive nodes. An overlapping region of a drivingelectrode and a sensing electrode may form a capacitive node, and thedriving electrode and the sensing electrode may be coupled with eachother in a capacitive manner across space therebetween. A driving signalapplied to a driving electrode (TX) by a touch control circuit (acontrol circuit configured for touch detection) may induce charges onthe sensing electrodes based on the coupled mutual-capacitance, and theamount of induced charges may be easily affected by external influence(e.g., touch or approach of an object).

The touch control circuit provides touch sensing signals to a processingapparatus (e.g., a CPU, etc.) by measuring a capacitance change of theentire mutual-capacitance array formed by the driving electrodes and thesensing electrodes, for the processing apparatus to determine a positionor proximity of touch within a touch sensitive region of the touchsensor. In a case of a touch display apparatus or a touch displayapparatus with a fingerprint recognition function, the processingapparatus may also interact with a display driving circuit and/or afingerprint recognition control circuit, to control a display operationand a fingerprint recognition operation.

With respect to the touch detection process for the touch panel, it isalways the objective of the industry that low noise and low powerconsumption are achieved as much as possible so as to improve detectionaccuracy and reduce power consumption costs.

SUMMARY

The present disclosure is intended to provide a touch driving apparatusand a touch driving method, so as to achieve the objective of low noiseand low power consumption in the touch detection process.

According to an aspect of present application, a touch driving apparatusused for a touch sensor is provided. The touch sensor comprises aplurality of driving electrodes and a plurality of sensing electrodesintersecting with each other, and the touch driving apparatus comprises:at least one output module, each output module comprising at least twooutput stage circuits, each output stage circuit having an outputterminal configured to output a driving signal to a connected drivingelectrode; a controller, configured to: for each output module,determine a first output stage circuit group and a second output stagecircuit group in the current driving time period according to a CodeDivision Multiple Access (CDM) code matrix, wherein, a first drivingsignal group at an output terminal of the first output stage circuitgroup is expected to discharge a first driving electrode group, and asecond driving signal group at an output terminal of the second outputstage circuit group is expected to charge a second driving electrodegroup; and control utilizing power from the first driving electrodegroup to charge the second driving electrode group, in response to thedetermination.

According to another aspect of present application, a touch controlapparatus used for a touch sensor is provided A touch control apparatus,comprising: a touch panel, comprising a touch sensor comprising aplurality of driving electrodes and a plurality of sensing electrodesintersecting with each other; the touch driving apparatus as describedabove, wherein, the touch driving apparatus is configured to supplydriving signals to the plurality of driving electrodes on the touchpanel.

According to another aspect of present application, a touch drivingmethod used for a touch sensor is provided. The touch sensor comprises aplurality of driving electrodes and a plurality of sensing electrodesintersecting with each other; the plurality of driving electrodes aredivided into at least one group; each group corresponds to an outputmodule; and each output module comprises output stage circuits whosenumber is equal to that of driving electrodes of each group. The methodcomprises: for each output module, determining a first output stagecircuit group and a second output stage circuit group in the currentdriving time period according to a Code Division Multiple Access (CDM)code matrix, wherein, a first driving signal group at an output terminalof the first output stage circuit group is expected to discharge a firstdriving electrode group, and a second driving signal group at an outputterminal of the second output stage circuit group is expected to chargea second driving electrode group; and controlling utilizing power fromthe first driving electrode group to charge the second driving electrodegroup, in response to the determination.

Based on the touch driving apparatus, the touch control apparatus andthe touch driving method as described in the present disclosure, bymodularizing a plurality of output stage circuits corresponding to aplurality of driving electrodes on a touch panel, driving signals may begenerated and controlled for each output module; secondly, in a processof generating the driving signals in a code division multiple accessmode, a path switch(es) between driving electrodes is provided by takingadvantage of a characteristics that driving signals may have energyinteraction with each other, so that a charge-discharge process betweenthe driving electrodes may be performed, and thus the power that thetouch driving apparatus needs to supply to the driving electrodes mayalso be reduced while improving detection accuracy and reducinginterference by adopting the code division multiple access, and thus,power consumption may be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a structural schematic diagram of a touch control apparatusaccording to an embodiment of the present disclosure.

FIG. 2A shows an exemplary touch sensor in combination with TimeDivision Multiplexing (TDM) according to an embodiment of the presentdisclosure.

FIG. 2B shows an exemplary touch sensor in combination with CodeDivision Multiplexing (CDM) according to an embodiment of the presentdisclosure.

FIG. 2C illustrates a schematic diagram of a driving waveformcorresponding to a Hadamard code matrix.

FIG. 3 shows a schematic diagram of an output stage circuit according toan embodiment of the present disclosure.

FIG. 4 shows a structural schematic diagram of a touch driving apparatusused for a touch panel according to an embodiment of the presentdisclosure.

FIG. 5 shows a structural schematic diagram of another touch drivingapparatus used for a touch panel according to an embodiment of thepresent disclosure.

FIG. 6A to FIG. 6B show schematic diagrams of a charge-discharge path(s)arranged between every two output stage circuits according to anembodiment of the present disclosure.

FIG. 7A to FIG. 7D show schematic diagrams of a charge-discharge path(s)between every two output stage circuits by adopting a charge sharing busaccording to an embodiment of the present disclosure.

FIG. 8 to FIG. 13 shows schematic structures of a touch drivingapparatus including a comparing unit(s) according to an embodiment ofthe present disclosure.

FIG. 14 shows a schematic flow chart of a method of a touch drivingapparatus used for a touch panel according to an embodiment of thepresent disclosure.

DETAILED DESCRIPTION

In order to make objectives, technical details and advantages of theembodiments of the present disclosure apparent, the technical solutionsof the embodiment will be described in a clearly and fullyunderstandable way in connection with the drawings related to theembodiments of the present disclosure. It is obvious that the describedembodiments are just a part but not all of the embodiments of thepresent disclosure. Based on the described embodiments herein, otherembodiment(s) which can be acquired by those ordinarily skilled in theart without any inventive labor should be within the scope of thepresent disclosure.

Unless otherwise defined, the technical or scientific terms used in thepresent disclosure shall have the usual meanings understood by personsof ordinary skill in the field to which the present disclosure belongs.The terms “first”, “second” and similar words used in the presentdisclosure do not indicate any order, quantity or importance, but areonly used to distinguish different components. Similarly, words such as“one”, “a/an” or “the” or the like do not denote quantitativelimitation, but rather indicate that there is at least one. Words suchas “include” or “comprise” and/or the like denote that elements orobjects appearing before the words of “include” or “comprise” cover theelements or the objects enumerated after the words of “include” or“comprise” or equivalents thereof, not exclusive of other elements orobjects. Words such as “connect to” or “connect with” and/or the likeare not limited to physical or mechanical connections, but may includeelectrical connection, either direct or indirect. Words such as “up”,“down”, “left”, “right” and/or the like are only used for expressingrelative positional relationship, when the absolute position of thedescribed object is changed, the relative positional relationship mayalso be correspondingly changed.

FIG. 1 shows a structural schematic diagram of a touch control apparatusaccording to an embodiment of the present disclosure.

As shown in FIG. 1 , the touch control apparatus 100 includes a touchcontrol circuit 101 and a touch sensor 102.

The touch control circuit 101 includes a signal generator 111, a driver121, a flexible circuit board pad 131, a flexible circuit board pad 141,an amplifier 151, a multi-selector 161, a filter 171, a memory 181, etc.

The touch sensor 102 includes a plurality of TX lines (drivingelectrodes) and a plurality of RX lines (sensing electrodes). Acapacitor will be formed at an intersection of a TX line and an RX line,that is, the TX line and the RX line respectively form two electrodes ofthe capacitor. The driver 121 is electrically connected with the TX linethrough the flexible circuit board pad 131, to transmit a driving signalto the TX line. The driving signal may be, for example, a noiselesscarrier signal of a predetermined frequency. After the driver 121transmits the driving signal to the TX line, for example, the samecarrier signal may be used to amplify and demodulate a signal from theRX line through the amplifier 151, the multi-selector 161, and thefilter 171.

The touch control circuit may apply driving signals to the plurality ofdriving electrodes of the touch sensor, receive touch sensing signalsfrom the plurality of sensing electrodes of the touch sensor, processthe received touch sensing signals, and supply the same to a processingapparatus (e.g., a processor, a MCU, a DSP, an ASIC or a combinationthereof, etc.), so that the processing apparatus may determine aposition of a finger or other object, etc. that contacts or approachesthe touch sensor. The touch control circuit may be integrated into onechip. In addition, in a case of a touch display apparatus or a touchdisplay apparatus with a fingerprint recognition function, theprocessing apparatus may also interact with a display driver circuitand/or a fingerprint recognition control circuit, to control a displayoperation and a fingerprint recognition operation. Meanwhile, at least aportion of the touch control circuit, the display driver circuit and/orthe fingerprint recognition control circuit may be integrated into onechip, for example, a Touch and Display Driver Integration (TDDI) chipand a Fingerprint Touch Display Integration (FTDI) chip.

The touch control apparatus 100 may include various electronic deviceshaving a touch function (or may also include a display function and/or afingerprint recognition function, etc.), for example, but not limitedto, a mobile phone, a tablet personal computer, a personal digitalassistant, a wearable device, and so on.

FIG. 2A illustrates an exemplary touch sensor in combination with TimeDivision Multiplexing (TDM) according to an embodiment of the presentdisclosure. FIG. 2B illustrates an exemplary touch sensor in combinationwith Code Division Multiplexing (CDM) according to an embodiment of thepresent disclosure. FIG. 2C illustrates a schematic diagram of a drivingwaveform corresponding to a Hadamard code matrix.

A Time Division Multiplexing (TDM) solution may be adopted whenmeasuring mutual capacitances at respective intersections during touchdetection process, that is, the driving electrodes are sequentiallyscanned with a preset noiseless driving signal (e.g., a carrier signal)at different times, and electrical signals are read(sensed) from allsensing electrodes at each time (e.g., then amplifying and demodulatingwith a same carrier signal). However, such a solution may lead to a longsensing time, because it is necessary to read the electrical signalsfrom all sensing electrodes with respect to each driving electrode in atime-sharing manner. In addition, the touch sensor design using the TDMsolution cannot fully solve the problem of occurrence of noise signalson the sensing electrodes that may be attributed to environment or othertypes of interference, which may cause a low Signal-to-Noise Ratio (SNR)of the sensed electrical signals.

As an improvement on Time Division Multiplexing (TDM), Code DivisionMultiplexing (CDM) may be adopted. In the CDM solution, a group ofdriving electrodes may be selected simultaneously, and a driving signalgroups corresponding to a preset CDM code matrix (a matrix size isdetermined by the number of driving electrodes in each group) may beprovided. For example, a reference driving signal may be coded with apreset code matrix, to obtain the driving signals corresponding to thepreset CDM code matrix used for the group of driving electrodes; then,result codes obtained for all the sensing electrodes are demodulated,for example, the result codes are demodulated by multiplying the resultcodes with an inverse matrix of the preset CDM code matrix, so that avalue of the mutual capacitance at the intersection of each drivingelectrode and each sensing electrode may be obtained, to furtherdetermine whether there is a change.

For example, the preset CDM code matrix which is a Hadamard code matrixof 4×4 encoding the reference driving signal to obtain the drivingsignals for four driving electrodes is taken as an example, and in theHadamard code matrix, an inner product of any different rows (columns)is 0. The Hadamard code of 4×4 may be expressed as follows:

$\begin{bmatrix}1 & 1 & 1 & 1 \\1 & {- 1} & 1 & {- 1} \\1 & 1 & {- 1} & {- 1} \\1 & {- 1} & {- 1} & 1\end{bmatrix}$

Accordingly, a driving waveform corresponding to the Hadamard codematrix may be as shown in FIG. 2C.

In FIG. 2C, a horizontal direction is a time axis direction, and fourdriving signals are applied simultaneously to the driving electrodesTX[N], TX[N+1], TX[N+2] and TX[N+3]. Each code value in the code matrixcorresponds to a waveform of a driving signal applied in a code segment(having a preset duration). For example, when the code value is 1, thewaveform of the applied driving signal (within a code segment) is thesame as a waveform of the reference driving signal; when the code valueis −1, the waveform of the applied driving signal (within a codesegment) is a waveform that lags 180° behind the reference drivingsignal.

Of course, the Hadamard code matrix is only an example of encoding andobtaining the driving signals; other codes may also be used for encodingthe reference driving signal, and a dimension of the matrix may also beselected as needed. For example, a proprietary code matrix may be used.The proprietary code matrix includes codes that may balance a sum ofcode values 1 and −1 for each driving electrode in each code segment,which is close to zero (the so-called DC balance codes), which mayreduce coupling noises entering the display panel due to a path formedby the parasitic capacitance between the driving electrode and a displayelectrode in the display panel (e.g., a gate, a data line, and/or acommon electrode), and thus may reduce visual artifacts and improvedisplay quality. Of course, the Hadamard code matrix may also reduce thesum of the code values 1 and −1 for each driving electrode in each codesegment to a certain extent, which may also reduce the noises andimprove the display quality.

In addition, the CDM solution is used, for example, for distributingmultiplexed driving signals into many frequencies by encoding, which mayavoid intra-band interference between a driving-sensing electrode pair(a driving electrode and all sensing electrodes are referred to as adriving-sensing pair), so that the signal-to-noise ratio of the sensedsignals of the touch sensor may also be increased.

In some cases, the touch control circuit adopts a square wave signal asthe driving signal, as shown in FIG. 2C. Of course, the driving signalmay also include a triangle wave signal, a sine wave signal or othersignal with a different type.

In addition, a power supply of the touch control circuit usually has alow voltage value. For example, with respect to a case where the touchcontrol apparatus is a mobile phone whose battery may only supply avoltage signal of an amplitude of about 3.3 V, but an amplitude of thedriving signal may be, for example, 6 V, so a boost circuit needs to beprovided in the touch control circuit to boost the voltage signal, so asto obtain the amplitude required by the driving signal.

In a case of using the CDM solution, when driving signals are applied tothe driving electrodes, and when each driving signal charges mutualcapacitors on the corresponding driving electrode in the touch sensor, acurrent supplied to the touch sensor may be approximately an expressionshown in Equation 1, and it is assumed in the expression that eachdriving electrode is fully charged by the applied driving signal.

I=N×C _(TX) ×F×V  (1)

where, I is an average value of the current supplied to the drivingelectrodes from the touch control circuit, N is the number of drivingelectrodes, C_(TX) is total capacitance of mutual capacitors on eachdriving electrode, F is a carrier frequency for measurement, and V is anamplitude of the driving signal.

In a typical case, N=17, C_(TX)=500 pF, F=180 kHz, V=6 V; so it may bederived that 1=17×500 pF×180 kHz×6V=9 mA.

In addition, measurement for capacitance of mutual capacitors is usuallycarried out at 120 Hz, and each scanning duration is 2 ms, so a totalduty cycle is 24%. Besides, the boost circuit and other related circuitsmay usually operate at 90% efficiency, so driving power consumption ofthe touch control circuit may be calculated as follows:

$\begin{matrix}{{Power} = {{V \times I \times {Duty} \times ( {1 + ( {1 - {efficiency}} )} )} = {{9{mA} \times 6V \times 24\% \times 110\%} = {15{mW}}}}} & (2)\end{matrix}$

Such power consumption is quite obvious in a typical touch controlcircuit, thereby reducing efficiency of the touch control circuit duringthe touch detection operation.

Therefore, the present disclosure proposes a solution that can reducepower consumption of the touch control circuit when performing the touchdetection operation, thereby improving efficiency.

Firstly, an output stage circuit for the driving signals in the touchcontrol circuit is briefly introduced. FIG. 3 shows a schematic diagramof an output stage circuit according to an embodiment of the presentdisclosure.

The output stage circuit may shape (e.g., generate a square wave drivingsignal) or improve, denoise, etc. for each driving control signal in thetouch control circuit, so that a waveform of the driving signal meetsdesign requirements. Optionally, the output stage circuit may beintegrated into a same chip with the touch control circuit for touchdetection, but may also be independent of the touch control circuit.

It should be understood that the output stage circuit shown in FIG. 3 isonly an example, and may be other circuit that is capable of improvingor shaping a waveform of the input driving control signal to obtain adriving signal. In addition, it should be noted that although mostcontents of the present disclosure have been illustrated by taking thata controller provides the driving signal to a corresponding drivingelectrode via the output stage circuit as an example, yet in someembodiments, the controller may directly provides the driving signal toa driving electrode without providing an output stage circuit.

As shown in FIG. 3 , the output stage circuit may include a first switchand a second switch connected in series between a high-level powersupply terminal (supplying a preset high level TX VDD, for example, 6V)and a low-level power supply terminal (e.g., providing a preset lowlevel 0 V); and a connection node of the first switch and the secondswitch is connected to an output terminal of the output stage circuit.

Optionally, the output stage circuit includes a series branch of twotransistors (T1 and T2) having opposite polarities. The first transistorT1 (e.g., a P-type transistor) on an upper side has a first terminalconnected with a high-level power supply terminal (having a preset highlevel TX VDD, for example, 6 V), a second terminal connected with afirst terminal of the second transistor T2 on a lower side, and acontrol terminal configured to receive a driving control signal. Thesecond transistor T2 (e.g., an N-type transistor) on the lower side hasa first terminal connected with the second terminal of the firsttransistor T1 on the upper side, a second terminal connected with thelow-level power supply terminal (having a preset low level, for example,zero), and a control terminal also configured to receive the samedriving control signal as the first transistor T1. A connection node ofthe first transistor T1 on the upper side and the second transistor T2on the lower side is connected to the output terminal OUTPUT of theoutput stage circuit for outputting a driving signal applied to acorresponding driving electrode. Hereinafter, the “driving signal” asmentioned refers to the driving signal at the output terminal of theoutput stage circuit.

Of course, transistors T1 and T2 may also be other forms of transistors,and may be controlled by independent control signals, as long as theymay be turned on and off to output the driving signal whose voltagevalue changes periodically between the preset high level and the presetlow level. For example, T1 and T2 are transistors of a same type; acontrol signal for transistor T1 is the same as the driving controlsignal, and a control signal for transistor T2 is an inverse signal ofthe driving control signal.

Based on the circuit shown in FIG. 3 , when the level of the drivingcontrol signal Scon exceeds a first threshold level, the transistor T2is turned on, the transistor T1 is turned off, and an output at theoutput terminal OUTPUT is at the preset low level; when the level of thedriving control signal Scon is lower than a second threshold level, thetransistor T2 is turned off, the transistor T1 is turned on, and anoutput at the output terminal OUTPUT is at the preset high level,wherein, values of the first threshold level and the second thresholdlevel are determined by parameters of the transistors (e.g., a thresholdvoltage Vth). Therefore, the amplitude of the driving signal TXdrvoutput from the output terminal OUTPUT changes between the preset highlevel and the preset low level, so signal quality is relatively good;and by setting the value of the preset high level, the output drivingsignal may be ensured to have sufficient driving capability.

Returning to power consumption calculation of the touch control circuit,power consumption calculated with reference to Equations (1) to (2)above is performed based on the current that a power supply (e.g., thehigh-level power supply end in FIG. 3 ) charges mutual capacitors oneach driving electrode and the current that mutual capacitors on eachdriving electrode discharges to a reference terminal (e.g., the lowlevel power supply terminal in FIG. 3 ).

Considering that in the CDM method, in each code segment, there may beinverse code values (e.g., 1 and −1), and corresponding driving signalsmay have phase shift, so an amplitude difference of at least two drivingsignals during each driving time period (e.g., half of a driving cycle)included in the code segment will be great enough, for example, withrespect to the driving signal applied to the first driving electrode, avoltage value at the end of a previous driving time period is 6 V, andan expected voltage value in the current driving time period is 0 V,meanwhile, with respect to the driving signal applied to the seconddriving electrode, a voltage value at the end of a previous driving timeperiod is 0 V, and an expected voltage value in the current driving timeperiod is 6 V. Therefore, the driving signals applied to differentdriving electrodes in the current driving time period are expected todischarge mutual capacitors on the first driving electrode of thedifferent driving electrodes, while charging the mutual capacitors onthe second driving electrode of the different driving electrodes, atthis time, the solution proposed in the present disclosure may utilizeat least a portion of power released by the mutual capacitors on thefirst driving electrode to charge the mutual capacitors on the seconddriving electrode, which, thus, may reduce power absorbed from the touchcontrol circuit (e.g., an internal power supply that supplies 6 Vvoltage), thereby reducing power consumption of the touch controlcircuit when performing the touch detection operation.

The touch driving apparatus and the touch driving method according tothe embodiments of the present disclosure will be described in detailbelow in conjunction with FIG. 4 to FIG. 9 .

FIG. 4 shows a structural schematic diagram of a touch driving apparatusused for a touch panel according to an embodiment of the presentdisclosure. Optionally, the touch driving apparatus may be the touchcontrol circuit as shown in FIG. 1 or included in the touch controlcircuit as shown in FIG. 1 . The touch panel includes a touch sensorcomprising a plurality of driving electrodes and a plurality of sensingelectrodes vertically intersecting with each other; and a mutualcapacitor is formed at each intersection of the plurality of drivingelectrodes and the plurality of sensing electrodes.

According to some embodiments, the touch driving apparatus may include acontroller.

The controller may determine a first driving electrode group and asecond driving electrode group in the current driving time periodaccording to a Code Division Multiple Access (CDM) code matrix, wherein,the first driving electrode group includes one or more drivingelectrode(s) among the plurality of driving electrodes that are expectedto be discharged in the current driving time period, and the seconddriving electrode group includes one or more driving electrode(s) amongthe plurality of driving electrodes that are expected to be charged inthe current driving time period; and the controller may controlutilizing power from the first driving electrode group to charge thesecond driving electrode group, in response to the determination.

For example, during a period when the first driving electrode groupcharges the second driving electrode group, the controller may notcontrol to supply any signal to the first driving electrode group andthe second driving electrode group; and the controller may control tosupply a low voltage to the first driving electrode group, for the firstdriving electrode group to release remaining power thereof aftercharging is completed, and supply a high level to the second drivingelectrode group, for the second driving electrode group to continuecharging.

Optionally, between the first driving electrode group and the seconddriving electrode group, there is a charge-discharge path(s) undercontrol of the controller.

Optionally, the touch driving apparatus may be modularized. In this way,the plurality of driving electrodes are divided into a plurality ofgroups, and the controller applies a same Code Division Multiple Access(CDM) code matrix to a control signal generated for each group.

According to some other embodiments, as described above, in order tobetter shape and improve the driving signal, and reduce requirements forthe controller function, an output stage circuit may be introduced, andeach output stage circuit has an input terminal configured to receivethe driving control signal from the controller, and an output terminalconfigured to output the driving signal to the connected drivingelectrode.

It should be understood that settings related to the output terminal ofthe output stage circuit hereinafter are also applicable to the outputterminal of the controller connected to the driving electrode withoutincluding the output stage circuit, for example, a path switch(s) isconnected between the output terminals of the controller, and/or a pathswitch(s) connected to the terminals of the controller is connected tothe charge sharing bus, etc.

As shown in FIG. 4 , the touch driving apparatus 400 may include: atleast one output module 410 and a controller 420.

The at least one output module 410 refers to modules (e.g., circuits)410-1, 410-2, . . . obtained by modularizing a plurality of output stagecircuits configured to supply driving signals to the plurality ofdriving electrodes. Each output module is connected to a drivingelectrode group on the touch panel, and the number of the drivingelectrode groups is equal to the number of output stage circuitsincluded in the output module.

For example, each output module includes at least two output stagecircuits 415-1, 415-2, . . . and an output terminal OUTPUT of eachoutput stage circuit is configured to output a driving signal to aconnected driving electrode. Of course, modularization may not beperformed, and at this time, all output stage circuits may be regardedas one output module.

Optionally, a structure of each output stage circuit 415-1, 415-2, . . .may be of the structure of the output stage circuit as described abovewith reference to FIG. 3 . Based on the input driving control signal, asquare wave signal switched between the preset high level TX VDD and thepreset low level may be obtained, as the driving signal supplied to thedriving electrode. The number of driving control signals input to eachoutput stage circuit may be one or more according to circuit structuresand device parameters of the output stage circuit.

The controller 420 may be configured to perform a same or similaroperation for each output module. For example, for each output module,the controller 420 may determine a first output stage circuit group anda second output stage circuit group in the current driving time periodaccording to the Code Division Multiple Access (CDM) code matrix,wherein, a first driving signal group at the output terminal(s) of thefirst output stage circuit group is expected to discharge the firstdriving electrode group, and a second driving signal group at the outputterminals of the second output stage circuit group is expected to chargethe second driving electrode group; and may control utilizing power fromthe first driving electrode group to charge the second driving electrodegroup, in response to the determination.

For example, the CDM code matrix may be a matrix adopted when using theCDM method to generate driving signals simultaneously applied torespective driving electrodes, as described above with reference to FIG.2B to FIG. 2C. The controller may acquire the preset CDM code matrixfrom the outside or read the preset CDM code matrix locally, and maydetermine timings of driving signals expected to be applied to eachdriving electrode in the current driving time period according to theCDM code matrix, so that the first output stage circuit group and thesecond output stage circuit group in the current driving time period maybe determined, wherein, the first driving signal group at the outputterminal(s) of the first output stage circuit group is expected todischarge the first driving electrode group, and the second drivingsignal group at the output terminal(s) of the second output stagecircuit group is expected to charge the second driving electrode group.According to the CDM code matrix, the first output stage circuit groupand the second output stage circuit group may each include one or moreoutput stage circuits. However, according to the CDM code matrix, duringa period corresponding to a certain code segment, for example, during aperiod corresponding to a first code segment in FIG. 2C, driving signalsapplied to respective driving electrodes are synchronous (e.g.,corresponding code values are all 1 or −1), at this time, there is onlythe first output stage circuit group or the second output stage circuitgroup, so there is no charge-discharge process between the drivingelectrodes as described later.

For example, the controller may firstly determine a timing of a drivingsignal corresponding to each driving electrode according to the CDM codematrix, wherein, each driving signal includes a plurality of drivingtime periods, and a duration of each driving time period is half of thecycle of the driving signal, as shown in FIG. 2C, a DT period is adriving time period; then, for each driving time period, the controllerfurther determines the first output stage circuit group and the secondoutput stage circuit group based on the determined timing of the drivingsignal corresponding to each driving electrode, and also controls eachoutput stage circuit based on a voltage value at an output terminal ofeach output stage circuit in the current driving time period (real-time,which will change with the charge-discharge process), for example, asdescribed later, controls ON and OFF of the switches in the output stagecircuits and ON and OFF of the path switch(es) between the output stagecircuits, to replace the charge-discharge process between the drivingelectrodes at an appropriate time, so as to charge the drivingelectrode(s) via a high-level power supply terminal and/or cause thedriving electrode(s) to discharge to the low-level power supplyterminal.

Optionally, the controller 420 may control utilizing the power from thefirst driving electrode group to charge the second driving electrodegroup up to the first time period when controlling the charge-dischargeprocess between the driving electrodes, and after the first time period,control releasing remaining power from the first driving electrode groupto the low-level power supply terminal, and utilizing the high-levelpower supply terminal to continue to charge the second driving electrodegroup.

For example, when the output stage circuit adopts the circuit structureas described in FIG. 3 , that is, each output stage circuit includes afirst switch T1 and a second switch T2 connected in series between thehigh-level power supply terminal and the low-level power supplyterminal, a connection node of the first switch T1 and the second switchT2 is connected to the output terminal of the output stage circuit; thecontroller may turn on the first switch of each output stage circuit andturn off the second switch, to utilize the high-level power supplyterminal to charge the driving electrode connected with the outputterminal of the output stage circuit; and turn on the second switch ofeach output stage circuit and turn off the first switch to release theremaining power from the driving electrode connected with the outputterminal of the output stage circuit to the low-level power supplyterminal (e.g., after an end of the charge-discharge process between thedriving electrodes, that is, after the first time period). In addition,the controller turns off both the first switch and the second switchincluded in each output stage circuit while controlling thecharge-discharge process between the driving electrodes (e.g., duringthe first time period).

That is to say, the power from the first driving electrode group mayonly supply a portion of the power needed to charge the second drivingelectrode group to the preset high level (e.g., TX VDD). For example,when voltages of these driving electrodes are equal or balanced afterthe charge-discharge process of the first time period, or when it isdetermined that the charge-discharge process between the drivingelectrodes should be stopped according to other conditions (e.g., thecurrent driving time period has started for a preset duration), thereshould be no or no more current flow between the driving electrodes, butat this time, the second driving electrode group has not been fullycharged (i.e., the voltage(s) thereon has not been charged to the presethigh level), and the voltage(s) on the first driving electrode group hasnot been released to the preset low level (e.g., 0), so, additionalpower supply is required to continue charging the second drivingelectrode group, and the remaining power on the first driving electrodegroup needs to be released.

Optionally, the controller may include various processing apparatusescapable of implementing the above-described control functions (e.g.,including but not limited to a CPU, a DSP, a FPGA, an ASIC, a MCU,etc.), and may also include storage apparatuses (e.g., including but notlimited to a memory such as RAM, ROM, etc., cache, or other types ofstorage apparatuses) for storing instructions, programs, information ordata, etc. required for implementing the above-described control ordetermination process. The controller may also include other circuits,components, firmware, etc. In addition, the controller may beimplemented by hardware circuits, software or a combination thereof.

By referring to the touch driving apparatus 400 as described in FIG. 4 ,a driving electrode that needs to release power may be utilized tocharge a driving electrode that needs to be charged; the touch drivingapparatus may supply power to the driving electrode that needs to becharged after the charge-discharge process has been started for a periodof time, so power that needs to be supplied to the driving electrode bythe touch driving apparatus may be reduced, which may reduce powerconsumption of the touch driving apparatus.

As further illustration of the touch driving apparatus described in FIG.4 , FIG. 5 shows a structural schematic diagram of another touch drivingapparatus used for a touch panel according to an embodiment of thepresent disclosure.

As shown in FIG. 5 , the touch driving apparatus 400 may further includeat least one path switch SW1, SW2 . . . , which is arranged betweenoutput terminals of every two output stage circuits among the at leasttwo output stage circuits in each output module, for providing acharge-discharge path(s) between the driving electrodes. Although notshown, the at least one path switch may also be a switch between eachoutput terminal and a charge sharing bus to be described later.Optionally, the path switch(es) may be provided in respective outputmodules (as shown in FIG. 6A), or independent of the output modules (asshown in FIG. 6B).

As described above, in each driving time period, whether a drivingsignal output by each output stage circuit is to charge or discharge theconnected driving electrode may be determined according to the CDM codematrix, so a driving electrode connected with each output stageelectrode circuit may be a driving electrode not to be discharged orcharged by another driving electrode (e.g., the code values are thesame), or may be a driving electrode to be charged by another drivingelectrode located in the output module or a driving electrode to releasepower to another driving electrode in the output module. Therefore, thepath switch(es) may be required between output terminals of every twooutput stage circuits among the at least two output stage circuits ineach output module, so that when a charge-discharge process betweendriving electrodes is required, the path switch(es) may provide one ormore corresponding charge-discharge paths under control of thecontroller.

For example, in combination with the structure of the output stagecircuit, during the first time period (the time period when power fromthe first driving electrode group is utilized to charge the seconddriving electrode group), the controller disables the first output stagecircuit group and the second output stage circuit group, and controlsturning on at least part of path switches, so that the power from thefirst driving electrode group charges the second driving electrodegroup; and after the first time period, the controller enables anconductive path between the output terminals of the first output stagecircuit group and the low-level power supply terminal as well as anconductive path between the high-level power supply terminal and theoutput terminals of the second output stage circuit group, and controlsturning off the at least part of path switches.

As an example, as shown in FIG. 6A, one output module includes twooutput stage circuits. Assuming that according to the CDM code matrix,it is determined that the first output stage circuit group in thecurrent driving time period includes a first output stage circuit(including switches T1 and T2), and the second output stage circuitgroup includes a second output stage circuit (including switches T3 andT4), a path switch T5 is provided between output terminals of the firstoutput stage circuit and the second output stage circuit. During thefirst time period, the controller controls turning on the path switch T5(without turning on the switches in the first output stage circuit andthe second output stage circuit), so that power from the first drivingelectrode connected with the first output stage circuit charges thesecond driving electrode connected with the second output stage circuitvia the path switch T5; after the first time period, the controllercontrols turning off the path switch T5. Thereafter, the controller maycontrol turning on the first switch T3 in the second output stagecircuit, so that the second driving electrode may be supplied with avoltage of a preset high level to continue to be charged, and controlturning on the second switch T2 of the first output stage circuit toconnect the first driving electrode to the low-voltage power supplyterminal having a preset low level, so that the first driving electrodemay continue to be discharged.

At a same time, as an example, the operation process of the outputmodule is briefly described in conjunction with a driving timingwaveform in FIG. 6A.

Firstly, at time point t0, when entering the current driving timeperiod, the controller determines according to the CDM code matrix thatan expected voltage value of the first driving electrode changes to 0from the preset high level of the previous driving time period, that is,it is expected to discharge the first driving electrode, meanwhile, anexpected voltage value of the second driving electrode changes to thepreset high level from 0 of the previous driving time period, that is,it is expected to charge the second driving electrode, so, thecontroller may determine to utilize the power on the first drivingelectrode to charge the second driving electrode, so, at this time, thecontroller controls turning on the path switch between the outputterminals of the first output stage circuit and the second output stagecircuit (e.g., the high level is considered as an active level in thediagram), so that a current may flow from the output terminal of thefirst output stage circuit to the output terminal of the second outputstage circuit, and turning off the switches in the first output stagecircuit and the second output stage circuit, that is, no powerinteraction is performed with the driving electrodes through the firstoutput stage circuit and the second output stage circuit at this time.

Starting from time point t0, switches T1 to T4 (which are assumed tohave a same type and be turned on at the high level) in the first outputstage circuit and the second output stage circuit are all turned off,and the path switch T5 is turned on, for example, the control signalsfor T1 to T4 shown in FIG. 6A are all at the low level, and the controlsignal for T5 is at the high level. Since the first driving electrodestarts to charge the second driving electrode via the path switch turnedon, a real-time voltage at the output terminal of the first output stagecircuit (corresponding to a real-time voltage on the first drivingelectrode) starts to drop gradually, while a real-time voltage at theoutput terminal of the second output stage circuit (corresponding to areal-time voltage on the second driving electrode) starts to risegradually.

At time point t1, the real-time voltage at the output terminal of thefirst output stage circuit drops to TX VDD/2, meanwhile, the real-timevoltage at the output terminal of the second output stage circuit risesto TX VDD/2, that is, the voltages on the first driving electrode andthe second driving electrode have reached equalization and thecharge-discharge process can no longer continue, or a voltage differencebetween the two voltages has met a threshold condition (e.g., within athreshold range), so the first time period corresponding to thecharge-discharge process ends, at this time, the path switch T5 isturned off, and the corresponding control signal for T5 becomes aninactive level (a low level), but the second driving electrode stillneeds to be charged and the first driving electrode still needs to bedischarged. Therefore, the second switch T2 on the lower side of thefirst output stage circuit is turned on (the first switch T1 on theupper side remains OFF), so that the first driving electrode continuesto be discharged to the low-level power supply terminal having thepreset low level, and the first switch T3 on the upper side of thesecond output stage circuit is turned on (the second switch T4 on thelower side remains OFF) so that the second driving electrode continuesto be charged by utilizing the preset high level of the high-level powersupply terminal until the end of the current driving time period.

It should be noted that in FIG. 6A, it is illustrated by taking only twodriving electrodes for the charge-discharge process as an example, so inthis case, an ideal condition for charge-discharge equalization isvoltages on the driving electrodes being TX VDD/2 (including ameasurement error range). In addition, according to the number ofdriving electrodes for the charge-discharge process, the idealconditions for charge-discharge equalization also vary. For example,when a ratio of the number of the driving electrodes to be discharged tothe number of driving electrodes to be charged is 1:2, the idealcondition for the charge-discharge equalization is the voltages on thedriving electrodes being TX VDD/3 (including a measurement error range).Meanwhile, different conditions may also be set to stop thecharge-discharge process without ideal equalization. For example, thecharge-discharge process will stop if the charge-discharge process hasproceeded for a predetermined duration or if a voltage differencebetween voltages on two driving electrodes which are to be charged andto be discharged is less than TX VDD/10.

Thereafter, at time point t2, the current driving time period ends, anda next driving time period serves as a new current driving time period.At this time, the second driving electrode starts to be discharged, andthe first driving electrode starts to be charged; then it is necessaryto turn on the path switch in a direction reverse to that of path switchin the previous driving time period, to supply power from the seconddriving electrode to the first driving electrode. Driving timings ofrespective switches in the process are similar to the driving timings inthe previous driving time period, and no details will be repeated here

As another example, as shown in FIG. 6B, an output module includes fouroutput stage circuits. For convenience of description, a specificstructure of the output stage circuit is omitted. For example, thespecific structure may be shown in FIG. 3 or be other availablestructure. In FIG. 6B, path switches are arranged between outputterminals of every two output stage circuits.

A driving principle of the output module shown in FIG. 6B is similar tothe driving principle of the output module shown in FIG. 6A. Assumingthat according to the CDM code matrix, it is determined that the firstoutput stage circuit group includes the first output stage circuit andthe second output stage circuit, and the second output stage circuitgroup includes a third output stage circuit and a fourth output stagecircuit. During the first time period, the controller controls turningon path switches between output terminals of the first output stagecircuit and the third output stage circuit, between output terminals ofthe first output stage circuit and the fourth output stage circuit,between output terminals of the second output stage circuit and thethird output stage circuit, and between output terminals of the secondoutput stage circuit and the third output stage circuit, so that powerfrom the first driving electrode and the second driving electrodeconnected with the first output stage circuit and the second outputstage circuit charges a third driving electrode and a fourth drivingelectrodes connected with the third output stage circuit and the fourthoutput stage circuit; and after the first time period, the controllercontrols turning off these path switches, controls the first switch andthe second switch in the first to the fourth output stage circuits, tosupply a voltage of a preset high level to the third driving electrodeand the fourth driving electrode, so that the third driving electrodeand the fourth driving electrode continue to be charged, and controlsconnecting the first driving electrode and the second driving electrodeto the low-voltage power supply terminal having a preset low level, sothat the first driving electrode and the second driving electrodecontinue to be discharged.

Or, in such case, when the first output stage circuit group and thesecond output stage circuit group each include at least two output stagecircuits, and path switches are provided between every two output stagecircuits, the controller may determine which path switch(es) betweenoutput terminals of the output stage circuits will be turned onaccording to a preset rule, and may make the driving electrodes to bedischarged be in one-to-one correspondence with the driving electrodesto be charged as far as possible, so as to simplify control logic, forexample, according to position distances from each other among thedriving electrodes connected with the output stage circuits, randomcombination, and/or equalizing the number of output stage circuitsconnected with the driving electrodes to be charged and the number ofoutput stage circuits connected with the driving electrodes to bedischarged as far as possible, and so on.

For example, the controller controls turning on the path switch betweenthe output terminals of the first output stage circuit and the thirdoutput stage circuit, so that power from the first driving electrodeconnected with the first output stage circuit charges the third drivingelectrode connected with the third output stage circuit, controlsturning on the path switch between the second output stage circuit andthe fourth output stage circuit, so that power from the second drivingelectrode connected with the second output stage circuit charges thefourth driving electrode connected with the fourth output stage circuit;and after the first time period, the controller controls turning offthese path switches, controls the first switch and the second switch inthe respective output stage circuits to supply a voltage of the presethigh level to the third driving electrode and the fourth drivingelectrode, so that the third driving electrode and the fourth drivingelectrode continue to be charged, and controls connecting the firstdriving electrode and the second driving electrode to the low-voltagepower supply terminal having the preset low level, so that the firstdriving electrode and the second driving electrode continue to bedischarged.

In addition, in a case of the output module shown in FIG. 6B, if in thecurrent driving time period, driving signals output by the second outputstage circuit and the third output stage circuit still need to maintainthe same level as in the previous driving time period, and thus thefirst output stage circuit group only includes the fourth output stagecircuit, and the second output stage circuit group only includes thefirst output stage circuit, the driving electrodes connected with thesecond output stage circuit and the third output stage circuit do notneed to be charged by another driving electrode or be discharged toanother driving electrode, so only the path switch from the outputterminal of the fourth output stage circuit to the output terminal ofthe first output stage circuit is turned on.

Driving timings of switches and path switches in the output stagecircuits as shown in FIG. 6B may also be deduced similarly according tothe driving timings in FIG. 6A, as long as the charge-discharge processbetween driving electrodes is guaranteed in the first time period of thecurrent driving time period.

As described above, in each output module, the path switch(es) isrequired between output terminals of every two output stage circuits,and each path switch is capable of providing a path for bidirectionalcurrent flow, so each of the path switches provided between outputterminals of every two output stage circuits is a single bidirectionalconduction switch (a single switch device) or a pair of unidirectionalconduction switches (two switch devices) with reverse conductiondirections. Optionally, each path switch may be a transistor of varioustypes.

An exemplary embodiment of how to use the path switch(es) to provide thecharge-discharge path(s) in the touch driving apparatus is describedabove with reference to FIG. 5 to FIG. 6B, and another exemplaryembodiment of how to use the path switch(es) and use a charge sharingbus to provide the charge-discharge paths will be described below withreference to FIG. 7A to FIG. 7D.

As shown in FIG. 7A to FIG. 7D, the touch driving apparatus 400 mayfurther include: at least one charge sharing bus; and an output terminalof each output stage circuit included in each output module isrespectively connected to the at least one charge sharing bus via acorresponding path switch, that is, each output terminal is switchablyconnected to each charge sharing bus via at least one path switch. Eachpath switch is a single bidirectional conduction switch or a pair ofunidirectional conduction switches with reverse conduction directions.Although an output terminal of each output stage circuit is connected tothe charge sharing bus via a corresponding path switch, it can be stillregarded as that there are path switches between output terminals ofevery two output stage circuits.

FIG. 7A shows an example in which there is one charge sharing bus, andthere are two output stage circuits included in each output module;wherein, the output terminal OUTPUT1 of the first output stage circuitand the output terminal OUTPUT2 of the second output stage circuit areboth connected to the charge sharing bus via a path switch (althoughshown as one path switch, it can represent a single bidirectionalconduction switch or a pair of unidirectional conduction switches withreverse ON directions). When the first driving electrode connected withthe output terminal OUTPUT1 of the first output stage circuit isexpected to charge the second driving electrode connected with theoutput terminal OUTPUT2 of the second output stage circuit, the pathswitch corresponding to the first output stage circuit is turned on inthe first direction, and the path switch corresponding to the secondoutput stage circuit is turned on in the second direction (or it is alsofeasible to turn on these path switches in both directionssimultaneously), so charging current will flow via the charge sharingbus, and vice versa.

FIG. 7B shows an example in which there are two charge sharing buses(e.g., the greater the number of buses is, the lower the path lossand/or the faster the charge-discharge speed may be), and there are twooutput stage circuits included in each output module, wherein the outputterminal OUTPUT1 of the first output stage circuit and the outputterminal OUTPUT2 of the second output stage circuit are each connectedto two charge sharing buses via two path switches. When the firstdriving electrode connected with the output terminal OUTPUT1 of thefirst output stage circuit is expected to charge the second drivingelectrode connected with the output terminal OUTPUT2 of the secondoutput stage circuit, the two path switches corresponding to the firstoutput stage circuit are turned on in the first direction, and the twopath switches corresponding to the second output stage circuit areturned on in the second direction (or it is also feasible to turn onthese path switches in both directions simultaneously), so that chargingcurrent will flow via these two charge sharing buses, and vice versa.

FIG. 7C shows an example in which there is one charge sharing bus, andthere are four output stage circuits included in each output module,wherein, the output terminals OUTPUT1 to OUTPUT4 of the first outputstage circuit to the fourth output stage circuit are each connected tothe charge sharing bus via one path switch. When driving electrodes inthe first driving electrode group connected with the output terminals ofoutput stage circuits in the first output stage circuit group (e.g., thefirst output stage circuit and the second output stage circuit) areexpected to charge driving electrodes in the second driving electrodegroup connected with the output terminals of output stage circuits inthe second output stage circuit group (e.g., the third output stagecircuit and the fourth output stage circuit), the path switchescorresponding to the first output stage circuit and the second outputstage circuit are turned on in the first direction, and the pathswitches corresponding to the third output stage circuit and the fourthoutput stage circuit are turned on in the second direction (or it isalso feasible to turn on these path switches in both directionssimultaneously), so that charging current flows via the charge sharingbus, and vice versa.

FIG. 7D shows an example in which there are two charge sharing buses,and there are four output stage circuits included in each output module,wherein, the output terminals OUTPUT1 to 4 of the first output stagecircuit to the fourth output stage circuit are each connected to the twocharge sharing buses via two path switches. When driving electrodes inthe first driving electrode group connected with the output terminals ofoutput stage circuits in the first output stage circuit group (e.g., thefirst output stage circuit and the second output stage circuit) areexpected to charge driving electrodes in the second driving electrodegroup connected with the output terminals of output stage circuits inthe second output stage circuit group (e.g., the third output stagecircuit and the fourth output stage circuit), the two path switchescorresponding to the first output stage circuit and the second outputstage circuit are turned on in the first direction, and the two pathswitches corresponding to the third output stage circuit and the fourthoutput stage circuit are turned on in the second direction (or it isalso feasible to turn on these path switches in both directionssimultaneously), so that charging current flows via the charge sharingbuses, and vice versa.

In the implementations described with reference to FIG. 7A to FIG. 7D,all driving electrodes to release power and all driving electrodes to becharged equalize charges thereof via the charge sharing bus, so as toimplement the charge-discharge process. Therefore, it is no longernecessary to provide path switches between output terminals of every twooutput stage circuits or select charge-discharge combinations of thepath switches, which, thus, may reduce the number of path switches, isfavorable for circuit layout and circuit volume reduction, and mayreduce complexity of control logic.

In the embodiments as described above with reference to FIG. 4 to FIG.7D, the charge-discharge process between the driving electrodes isperformed during the first time period; the first time period may bepreset; for example, according to experience, a time length between astart point of each driving time period and a predetermined time pointafter the start point may be taken as a time length of the first timeperiod. In addition, the first time period may also be determinedaccording to the charge-discharge process between the drivingelectrodes, for example, according to a first voltage value group at theoutput terminal(s) of the first output stage circuit group (fordischarging the first driving electrode group) and a second voltagevalue group at the output terminal(s) of the second output stage circuitgroup (for charging the second driving electrode group). For example, byproviding a comparing unit, the controller determines a time length ofthe first time period according to a comparison result of the comparingunit with respect to these voltage values and control logic. Thecomparing unit may be a software-implemented controller internal logicor a hardware circuit (included in the controller or independent of thecontroller and in the touch driving apparatus, e.g., a comparing circuitsuch as a comparator).

Hereinafter, a schematic structure of the comparing unit in the touchdriving apparatus used for the touch panel according to the embodimentof the present disclosure will be described with reference to FIG. 8 toFIG. 13 , wherein, the comparing unit is configured to determine an endof the first time period during which the charge-discharge processbetween the driving electrodes is performed. The start point of thefirst time period is a start point of each driving time period, forexample, a rising edge or a falling edge of a pulse of the drivingsignal.

It should be noted that the following is only exemplary description ofhow to use the comparing unit to determine the end of thecharge-discharge process (the end of the first time period) according tothe voltages at the output terminals of the output stage circuits;however, those skilled in the art should understand that other meansother than the comparing unit or other settings of the comparing unitmay also be adopted to determine the end of the charge-discharge processaccording to the voltages at the output terminals of the output stagecircuits, without departing from the protection scope claimed in thepresent disclosure.

For example, in some implementations, the touch driving apparatus mayinclude a plurality of comparing units; and for each comparing unit, oneterminal receives a voltage value at an output terminal of an outputstage circuit, and the other terminal receives a reference voltagevalue. When the number of output stage circuits whose output voltagevalues at respective output terminals and the corresponding referencevoltage value each meet a threshold condition (e.g., a difference issmall enough, e.g., the threshold is 0) is great enough, it isdetermined that the first time period ends. The reference voltage valuemay be determined according to a ratio of the number of drivingelectrodes to be charged and the number of driving electrodes to bedischarged (to achieve charge-discharge equalization), or any otherthreshold corresponding to the threshold condition (without reachingcharge-discharge equalization).

For example, as shown in FIG. 8 , the first output stage circuit groupincludes the first output stage circuit, the second output stage circuitgroup includes the second output stage circuit, and there is acharge-discharge path between the first output stage circuit and thesecond output stage circuit (the switch between the two is turned on orthe switches respectively connected to the charge sharing bus are turnedon); the manner of determining the first time period in FIG. 8 and thesubsequent drawings is exemplarily illustrated by taking the structureof the output module shown in FIG. 6A as an example, but it should beunderstood that the determining manner may be applied to other outputmodules (e.g., FIG. 6B to FIG. 7D). The first voltage value at theoutput terminal of the first output stage circuit and the second voltagevalue at the output terminal of the second output stage circuit arerespectively compared with the reference voltage value (Vref, forexample, TX VDD/2 or other preset reference values), if the differencebetween the first voltage value and the corresponding reference voltagevalue and the difference between the second voltage value and thecorresponding reference voltage value are both within a threshold range,it is determined that the first time period ends. Of course, the end ofthe first time period may also be determined if at least one of the twodifferences is within the threshold range, and this depends on controllogic design of the controller, which will not be limited in the presentdisclosure.

However, such determining manner requires a power supply that accuratelygenerates the reference voltage value. When the number of output stagecircuits in the output module is greater (there may be different ratiosof the number of driving electrodes to be charged to the number ofdriving electrodes to be discharged), more reference voltage values maybe required, and these reference voltage values need to be supplied bypower supply circuits, which may lead to increased complexity of thecircuit and control logic.

Therefore, in other implementation of the present disclosure, the firstvoltage value group output by the first output stage circuit group andthe second voltage value group output by the second output stage circuitgroup may be used as the inputs of the comparing unit, instead of thereference voltage value.

For example, the touch driving apparatus may include at least onecomparing unit. Each comparing unit of the at least one comparing unitcompares one voltage value of the first voltage value group with acorresponding one voltage value of the second voltage value group, andoutputs a comparison result indicating whether a voltage differencebetween the one voltage value of the first voltage value group and thecorresponding one voltage value of the second voltage value group meetsa threshold condition (e.g., the voltage difference between the twovoltage values is within a threshold range, or the voltage differencebetween a voltage component of one voltage of the two voltages and theother one voltage is within a threshold range, etc.). When the number ofcomparison results indicating the threshold condition being met isgreater than or equal to a first predetermined number, the controller420 determines that the first time period ends.

For example, as shown in FIG. 9 , output terminals of every two outputstage circuits of each output module are respectively connected to twoinput terminals of one comparing unit. The controller 420 may determinewhich comparing unit(s) should be enabled according to the determinedpath switch(s) which is turned on.

Optionally, the first preset number may be less than or equal to thenumber of the second voltage value groups, for example, half of thenumber of the second voltage value groups. Or, the first preset numbermay be, for example, half of the number of the first voltage valuegroups, which will not be limited in the present disclosure.

For example, the output module in FIG. 9 includes four output stagecircuits, the first output stage circuit group includes the first outputstage circuit 415-1 and the second output stage circuit 415-2, and thesecond output stage circuit group includes the third output stagecircuit 415-1 and the fourth output stage circuit 415-2. Comparing unitsare provided between output terminals of every two output stage circuits(as shown in FIG. 6A above, there are also path switches to implementthe charge-discharge paths). When the controller controls turning on thepath switch between the output terminals of the first output stagecircuit and the third output stage circuit (i.e., the driving electrodeconnected with the first output stage circuit discharges to the drivingelectrode connected with the third output stage circuit), and turning ona path switch between the output terminals of the second output stagecircuit and the fourth output stage circuit (i.e., the driving electrodeconnected with the second output stage circuit discharges to the drivingelectrode connected with the fourth output stage circuit), thecontroller enables a comparator Comp1 and a comparator Comp2, two inputterminals of the comparator Comp1 receive the voltage values of theoutput terminals of the first output stage circuit and the third outputstage circuit, and two input terminals of the comparator Comp2 receivethe voltage values of the output terminals of the second output stagecircuit and the fourth output stage circuit. When the voltage values ofthe output terminals of the first output stage circuit and the thirdoutput stage circuit meet a threshold condition (e.g., a voltagedifference of the two voltage values is within a threshold range) andthe voltage values of the output terminals of the second output stagecircuit and the fourth output stage circuit meet a threshold condition(e.g., a voltage difference of the two voltage values is within athreshold range), that is, the number of comparison results indicatingthe threshold conditions being met is 2 (equal to the number of thevoltage values in the second voltage value group), according to thecontrol logic design in the controller, the controller may determinethat the first time period ends.

Of course, as described above, the driving electrodes to be charged andthe driving electrodes to be discharged may not be in one-to-onecorrespondence with each other. For example, in FIG. 9 , when thedriving electrode corresponding to the first output stage circuit maysimultaneously charge the driving electrodes corresponding to the thirdoutput stage circuit and the fourth output stage circuit, the controllerneeds to turn on the path switches from the output terminal of the firstoutput stage circuit to the output terminals of the third output stagecircuit and the fourth output stage circuit, and enable the comparingunits connected between these output terminals. The second output stagecircuit is also similar thereto. Then, according to the results of thecomparing units and the control logic design in the controller, thecontroller 420 may determine that the first time period ends.

Additionally or alternatively, in a case where all output stage circuitsincluded in each output module are each connected to at least one chargesharing bus via a path switch, the time length of the first time periodmay also be determined by providing comparing units similar to thatdescribed with reference to FIG. 8 or FIG. 9 , that is, comparing unitsmay be connected between every two output terminals, and the controllerenables some of the comparing units according to the path switch(s)which is turned on.

However, considering that in the case of the at least one sharedcharging bus, the current in the charge-discharge process may flowbetween output terminals of any two output stage circuits correspondingto the driving electrodes to be charged and discharged via the at leastone charge sharing bus, and design parameters of each output stagecircuit are similar, therefore, in other implementations of the presentdisclosure, comparing units are not provided between output terminals ofevery two output stage circuits, but only a few comparing units, or evenone comparing unit need to be provided.

For example, the touch driving apparatus includes at least one comparingunit. Each comparing unit has one input terminal connected with anoutput terminal of a first representative output stage circuit in thefirst output stage circuit group to receive a first representativevoltage value, and the other input terminal connected with an outputterminal of a second representative output stage circuit in the secondoutput stage circuit group to receive a second representative voltagevalue, so as to obtain at least one comparison result; and when thenumber of comparison results indicating that the obtained firstrepresentative voltage value and the corresponding second representativevoltage value meet a threshold condition is greater than or equal to asecond preset number, the controller determines that the first timeperiod ends.

As shown in FIG. 10 , the touch driving apparatus includes a comparingunit Comp-t. Of course, according to the number of output stage circuitsin the output module, two or more comparing units may be provided, andthe connection manner of the input terminals of each comparing unit andthe output terminal of the output stage circuit is similar to that inFIG. 10 .

In FIG. 10 , it is illustrated by still taking that the output moduleincludes four output stage circuits, the first output stage circuitgroup includes the first output stage circuit 415-1 and the secondoutput stage circuit 415-2, and the second output stage circuit groupincludes the third output stage circuit 415-3 and the fourth outputstage circuit 415-4 as an example. The comparing unit Comp-t has oneinput terminal connected to the output terminal of the firstrepresentative output stage circuit in the first output stage circuitgroup, and the other input terminal connected to the output terminal ofthe second representative output stage circuit in the second outputstage circuit group. When the first representative voltage value at theoutput terminal of the first representative output stage circuit and thesecond representative voltage value at the output terminal of the secondrepresentative output stage circuit meet a threshold condition, thecontroller determines that the first time period ends.

For example, considering different combinations of output stage circuitsin the first output stage circuit group and the second output stagecircuit group, a determination manner of the first representative outputstage circuit and the second representative output stage circuit underdifferent possible combinations of output stage circuits may bepre-designed, as preset logic, in the controller. In a practicalapplication process, when the first output stage circuit group and thesecond output stage circuit group are determined, the firstrepresentative output stage circuit and the second representative outputstage circuit are determined according to the preset logic.

For example, the preset logic may include: with respect to a case wherethe first output stage circuit group includes the first output stagecircuit and the second output stage circuit group includes the secondoutput stage circuit to the fourth output stage circuit, the firstrepresentative output stage circuit is the first output stage circuitand the second representative output stage circuit is the third outputstage circuit. For another example, with respect to a case where thefirst output stage circuit group includes the first output stage circuitto the second output stage circuit and the second output stage circuitgroup includes the third output stage circuit to the fourth output stagecircuit, the first representative output stage circuit is the firstoutput stage circuit and the second representative output stage circuitis the fourth output stage circuit; and so on. Of course, this is onlyan example, and the determination manner of the first representativeoutput stage circuit and the second representative output stage circuitunder different possible combinations of output stage circuits may bepre-designed according to various factors.

In addition, when the touch driving apparatus includes more than onecomparing units, a determination manner of representative output stagecircuits under different possible combinations of output stage circuitsmay be similarly pre-designed.

For example, when there are two comparing units, the preset logic mayinclude: with respect to a case where the first output stage circuitgroup includes the first output stage circuit (i.e., 1 output stagecircuit), and the second output stage circuit group includes the secondoutput stage circuit to a sixth output stage circuit (i.e., 5 outputstage circuits), the representative output stage circuit in the firstoutput stage circuit group is the first output stage circuit, and itsoutput voltage value serves as an input of each of comparing units 1 and2; and, the two representative output stage circuits in the secondoutput stage circuit group are the third output stage circuit and thefourth output stage circuit, and their output voltage valuesrespectively serve as another input of each of comparing units 1 and 2.For another example, when there are two comparing units, with respect toa case where the first output stage circuit group includes the firstoutput stage circuit to the third output stage circuit, and the secondoutput stage circuit group includes the fourth output stage circuit tothe sixth output stage circuit, the two representative output stagecircuits in the first output stage circuit group are the first outputstage circuit and the third output stage circuit, and respectivelycorrespond to comparing units 1 and 2, the two representative outputstage circuits in the second output stage circuit group are the fifthoutput stage circuit and the sixth output stage circuit, andrespectively correspond to comparing units 1 and 2. Of course, this isonly an example, and the determination manner of the firstrepresentative output stage circuit and the second representative outputstage circuit under different possible combinations of output stagecircuits may be pre-designed according to various factors.

For example, the determination manner may be pre-designed according to acharge/discharge speed of an output terminal of each output stagecircuit, and the charge/discharge speed may be determined according toprevious operation state records and/or system parameters of theseoutput stage circuits. For example, the above-described firstrepresentative output stage circuit may be the one output stage circuitwith the slowest discharging speed in the first output stage circuitgroup, and the second representative output stage circuit may be the oneoutput stage circuit with the slowest charging speed in the secondoutput stage circuit group. Optionally, the respective output stagecircuits may be pre-ordered according to the charge/discharge speeds andsystem parameters, and the obtained order may be stored in the memory;when the first output stage circuit group and the second output stagecircuit group are determined, the output stage circuit with the slowestdischarging speed and the output stage circuit with the slowest chargingspeed respectively in the first output stage circuit group and thesecond output stage circuit group may be determined according to theorder, as the representative output stage circuits.

Of course, the first representative output stage circuit and the secondrepresentative output stage circuit may also be determined in othermanners.

In such implementation, the two input terminals of each comparing unitboth need to be capable of being connected to each output stage circuitin the output module. In some examples, output terminals of all outputstage circuits in the output module may be switchably connected with thetwo input terminals of each comparing unit through a one-to-moreswitching module. For example, a multi-selector or a multiplexer may beused, so that the controller may control which two output terminals(corresponding two output stage circuits) the two input terminals ofeach comparing unit should be connected to, by controlling theone-to-more switching module.

As shown in FIG. 11 , each output stage circuit in the output module isconnected to multi-selectors S1 and S2 or multiplexers MUX1 and MUX2(not shown), outputs of multi-selectors S1 and S2 or multiplexers MUX1and MUX2 are respectively connected to two input terminals of onecomparing unit. The controller controls multi-selectors S1 and S2 ormultiplexers MUX1 and MUX2 to switch for selection, so that thecomparing unit may be provided with the first representative voltagevalue and the second representative voltage value at the outputterminals of two output stage circuits. Of course, this is only anexample, and it is also feasible to adopt other switching manners, whichwill not be limited in the present disclosure.

With respect to a case where both terminals of the comparing unit areconnected with the output terminals of the output stage circuits,although most contents above are described with respect to a case wherethe charge-discharge process is stopped only when equalization betweenthe driving electrodes to be charged and the driving electrodes to bedischarged is reached, yet according to other implementations, thevoltage values of the driving electrodes to be discharged and thedriving electrodes to be charged are not necessarily equal (i.e., idealcharge-discharge equalization is not necessarily reached) so as to stopthe charge-discharge process. For example, other conditions fordetermining the end of the first time period may be adopted according toactual needs. For example, in a case where one driving electrodedischarges to another driving electrode, the first voltage value and thesecond voltage value on the discharging driving electrode and thecharging driving electrode are not necessarily both TX VDD/2 (with anerror range negligible) when determining end of the first time period(that the charge-discharge process should be stopped), but the end ofthe first time period may be determined when there is still a certaindifference between the first voltage value and the second voltage value.

To this end, the comparing unit may include a scaling sub-unit, which isconfigured to scale a voltage value of one input terminal of thecomparing unit, so that the scaled voltage value is compared with avoltage value of the other input terminal of the comparing unit. Theconditions for determining the end of the first time period may bechanged by presetting a scaling ratio. Optionally, the scaling sub-unitmay be a voltage divider circuit or a software-implemented controllerinternal logic.

For example, FIG. 12 shows a structural schematic diagram including acomparing unit with a scaling sub-unit.

As shown in FIG. 12 , after a voltage V1 at an output terminal OUTPUTmfrom one output stage circuit passes through a voltage divider circuitas a scaling sub-unit (e.g., implemented by connecting the resistors R1and R2 in series), a scaled voltage V1*R2/(R1+R2) is input to one inputterminal of the comparator, while a voltage V2 of an output terminalOUTPUTn of the other output stage circuit is input to another inputterminal of the comparator, so that when the value of V1*R2/(R1+R2) isalmost equal to the value of V2, the comparator outputs a comparisonresult indicating the end of the charge-discharge process betweendriving electrodes corresponding to the two output stage circuits (avoltage difference of the two voltages meets a threshold condition). Atthis time, when V1 and V2 are not equal, the comparator outputs thecomparison result.

According to other implementation, the touch driving apparatus mayinclude comparing units whose number is equal to the number of chargesharing buses; and the comparing units are in one-to-one correspondencewith the charge sharing buses. Each of the comparing units has a firstterminal connected with a corresponding charge sharing bus to obtain abus voltage value, and has a second terminal to acquire the referencevoltage value. At least one comparison result can be obtained. When thenumber of comparison results indicating that the bus voltage valueacquired from the corresponding charge sharing bus and the referencevoltage value meet a threshold condition is greater than or equal to athird preset number, the controller determines that the first timeperiod ends.

Optionally, the reference voltage value may be associated with thenumber of output stage circuits included in the first output stagecircuit group and the second output stage circuit group.

For example, as shown in FIG. 13 , the two comparing units Comp12-1 andComp12-2 have first terminals respectively connected to two chargesharing buses, and second terminals thereof respectively connected to avoltage source that supplies the reference voltage value. When acomparison result of at least one comparing unit indicates that avoltage difference between the bus voltage value and the referencevoltage value Vref (e.g., when the number of output stage circuitsincluded in the first output stage circuit group is equal to the numberof output stage circuits included in the second output stage circuitgroup, Vref is TX VDD/2) is small enough (i.e., the third preset numberis 1), the controller determines that the first time period ends.

The touch driving apparatus as described above with reference to FIG. 4to FIG. 13 has at least following advantages: firstly, the plurality ofoutput stage circuits corresponding to the plurality of drivingelectrodes on the touch panel are modularized, so that driving signalsmay be generated and controlled for each output module; secondly, byproviding the path switch(es) between the driving electrodes, thecharge-discharge process between the driving electrodes may beperformed, which may further reduce power that the touch drivingapparatus needs supply to the driving electrodes, and thus may reducepower consumption; next, all driving electrodes to release power and alldriving electrodes to be charged equalize charges by utilizing thecharge sharing bus, so as to implement the charge-discharge process, andtherefore, it is no longer necessary to provide path switch(es) betweenoutput terminals of every two output stage circuits or selectcharge-discharge combinations, which, thus, may reduce the number ofpath switches, is favorable for circuit layout and circuit volumereduction, and may further reduce complexity of control logic, therebypossessing obvious advantages especially in the case of more than twooutput stage circuits; finally, in some embodiments, voltage values atoutput terminals of the output stage circuits are as the input terminalsof the comparing unit(s), there is no need to provide one or moreadditional reference voltage sources, which simplifies circuit design;meanwhile, a scaling sub-unit is also provided in the comparing unit, sothat the conditions for stopping the charge-discharge process betweenthe driving electrodes may be flexibly designed, instead of stopping thecharge-discharge process between the driving electrodes only whendifferences between voltage values of the driving electrodes to becharged and driving electrodes to be discharged are substantially equal(within a measurement error range).

According to another aspect of the present disclosure, there is furtherprovided a method of the touch driving apparatus used for the touchpanel as described above with reference to FIG. 4 to FIG. 13 .

FIG. 14 shows a schematic flow chart of a method of a touch drivingapparatus used for a touch panel according to an embodiment of thepresent disclosure. The touch panel includes a plurality of drivingelectrodes and a plurality of sensing electrodes intersecting with eachother.

For example, in step S1410, a first output stage circuit group and asecond output stage circuit group in the current driving time period aredetermined according to a Code Division Multiple Access (CDM) codematrix, wherein, a first driving signal group at output terminals of thefirst output stage circuit group is expected to discharge the firstdriving electrode group, and a second driving signal group at outputterminals of the second output stage circuit group is expected to chargethe second driving electrode group.

Or, without including the output stage circuit, in step S1410, a firstdriving electrode group and a second driving electrode group in thecurrent driving time period are determined according to a Code DivisionMultiple Access (CDM) code matrix, wherein, the first driving electrodegroup includes one or more driving electrodes that are expected to bedischarged in the current driving time period among the plurality ofdriving electrodes, and the second driving electrode group includes oneor more driving electrodes that are expected to be charged in thecurrent driving time period among the plurality of driving electrodes.

In step S1420, in response to the determination, it is controlled toutilize power from the first driving electrode group to charge thesecond driving electrode group.

Optionally, the plurality of driving electrodes are divided into atleast one group; each group corresponds to an output module; each outputmodule includes at least two output stage circuits; and each outputstage circuit outputs a driving signal to the connected drivingelectrode based on the driving control signal. The method shown in FIG.14 is carried out for each output module, that is, the Code DivisionMultiple Access (CDM) code matrix corresponds to each output module; andfor each output module, the output terminal(s) of the first output stagecircuit group is connected with the first driving electrode group, andthe output terminal(s) of the second output stage circuit group isconnected with the second driving electrode group.

Optionally, similar to the contents as described above with reference toFIG. 4 to FIG. 13 , specifically, in step S1420, the first output stagecircuit group and the second output stage circuit group are controlledto utilize power from the first driving electrode group to charge thesecond driving electrode group up to the first time period; and afterthe first time period, the first output stage circuit group and thesecond output stage circuit group are controlled so that remaining powerfrom the first driving electrode group is released to the low-levelpower supply terminal, and the second driving electrode group continueto be charged by utilizing the power from the high-level power supplyterminal.

For example, in order to implement the path for current to flow, atleast one path switch is provided between output terminals of every twooutput stage circuits in the output stage circuits included in eachoutput module. Within the first time period, the controller disables thefirst output stage circuit group and the second output stage circuitgroup, and controls turning on at least part of the path switch (es), sothat power from the first driving electrode group charges the seconddriving electrode group. After the first time period, the controllerenables an conductive path(s) between the output terminal(s) of thefirst output stage circuit group and the low-level power supply terminalas well as an conductive path(s) between the high-level power supplyterminal and the output terminal(s) of the second output stage circuitgroup, and controls turning off the at least part of the path switches.

More details of the method shown in FIG. 14 are the same or similar tothe contents described above for the touch driving apparatus used forthe touch panel. Due to the description above, no details will berepeated here.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of various aspects. In fact, many ofthese features may be combined in ways not specifically recited in theclaims and/or disclosed in the specification. Although each dependentclaim listed below may directly depend on only one claim, the disclosureof various aspects includes each dependent claim in combination withevery other claim in the claim set. A phrase referring to “at least oneof” a list of items refers to any combination of those items, includingsingle members. As an example, “at least one of: a, b, or c” is intendedto cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combinationwith multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c,a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering ofa, b, and c).

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems and may be used interchangeably with “one or more.” Further, asused herein, the article “the” is intended to include one or more itemsreferenced in connection with the article “the” and may be usedinterchangeably with “the one or more.” Furthermore, as used herein, theterms “set” and “group” are intended to include one or more items (e.g.,related items, unrelated items, a combination of related and unrelateditems, and/or the like), and may be used interchangeably with “one ormore.” Where only one item is intended, the phrase “only one” or similarlanguage is used. Also, as used herein, the terms “has,” “have,”“having,” and/or the like are intended to be open-ended terms. Further,the phrase “based on” is intended to mean “based, at least in part, on”unless explicitly stated otherwise. Also, as used herein, the term “or”is intended to be inclusive when used in a series and may be usedinterchangeably with “and/or,” unless explicitly stated otherwise (e.g.,if used in combination with “either” or “only one of”).

Several points below need to be explained:

-   -   (1) The drawings of the embodiments of the present disclosure        relate only to the structures involved in the embodiments of the        present disclosure, and normal designs may be referred to for        other structures.    -   (2) In case of no conflict, the embodiments of the present        disclosure and the features in the embodiments may be combined        with each other to obtain a new embodiment.

The above are only specific embodiments of the present disclosure, butthe scope of the embodiment of the present disclosure is not limitedthereto, and the scope of the present disclosure should be the scope ofthe following claims.

1. A touch driving apparatus used for a touch sensor, wherein, the touchsensor comprises a plurality of driving electrodes and a plurality ofsensing electrodes intersecting with each other, and the touch drivingapparatus comprises: at least one output module, each output modulecomprising at least two output stage circuits, each output stage circuithaving an output terminal configured to output a driving signal to aconnected driving electrode; a controller, configured to: for eachoutput module, determine a first output stage circuit group and a secondoutput stage circuit group in the current driving time period accordingto a Code Division Multiple Access (CDM) code matrix, wherein, a firstdriving signal group at an output terminal of the first output stagecircuit group is expected to discharge a first driving electrode group,and a second driving signal group at an output terminal of the secondoutput stage circuit group is expected to charge a second drivingelectrode group; and control utilizing power from the first drivingelectrode group to charge the second driving electrode group, inresponse to the determination.
 2. The touch driving apparatus accordingto claim 1, wherein, the controller controls the first output stagecircuit group and the second output stage circuit group, to: utilize thepower from the first driving electrode group to charge the seconddriving electrode group up to a first time period; and after the firsttime period, release remaining power from the first driving electrodegroup to a low-level power supply terminal, and utilize a high-levelpower supply terminal to charge the second driving electrode group. 3.The touch driving apparatus according to claim 2, further comprising: atleast one path switch, arranged between output terminals of every twooutput stage circuits in the at least two output stage circuits,wherein, in the first time period, the controller disables the firstoutput stage circuit group and the second output stage circuit group,and controls turning on at least part of the at least one path switch,so that the power from the first driving electrode group charges thesecond driving electrode group; and after the first time period, thecontroller enables a conductive path between the output terminal of thefirst output stage circuit group and a low-level power supply terminalas well as a conductive path between a high-level power supply terminaland the output terminal of the second output stage circuit group, andcontrols turning off the at least part of the at least one path switch.4. The touch driving apparatus according to claim 3, further comprising:at least one charge sharing bus, wherein, an output terminal of eachoutput stage circuit in the at least two output stage circuits isconnected to the at least one charge sharing bus via a correspondingpath switch, and each path switch is a single bidirectional conductiveswitch or a pair of unidirectional conductive switches with reverseconductive directions.
 5. The touch driving apparatus according to claim4, wherein, a duration of the first time period is preset, or an end ofthe first time period is determined according to a first voltage valuegroup at the output terminal of the first output stage circuit group anda second voltage value group at the output terminal of the second outputstage circuit group.
 6. The touch driving apparatus according to claim5, wherein, the touch driving apparatus comprises at least one comparingunit; and each comparing unit compares one voltage value of the firstvoltage value group with a corresponding one voltage value of the secondvoltage value group, and outputs a comparison result indicating whethera voltage difference between the one voltage value of the first voltagevalue group and the corresponding one voltage value of the secondvoltage value group meets a threshold condition, wherein, when a numberof comparison results indicating the threshold condition being met isgreater than or equal to a first preset number, the controllerdetermines that the first time period ends.
 7. The touch drivingapparatus according to claim 6, wherein, output terminals of every twooutput stage circuits are respectively connected to two input terminalsof one comparing unit; wherein, the controller determines a comparingunit to be enabled according to the determined conductive path switchwhich is turned on.
 8. The touch driving apparatus according to claim 5,wherein, the touch driving apparatus comprises at least one comparingunit, each comparing unit has a first input terminal connected with anoutput terminal of a first representative output stage circuit in thefirst output stage circuit group to obtain a first representativevoltage value, and a second input terminal connected with an outputterminal of a second representative output stage circuit in the secondoutput stage circuit group to obtain a second representative voltagevalue, so to obtain at least one comparison result; and when a number ofcomparison results indicating that the first representative voltagevalue and a corresponding second representative voltage value meet athreshold condition is greater than or equal to a second preset number,the controller determines that the first time period ends.
 9. The touchdriving apparatus according to claim 6, wherein, the comparing unitcomprises a scaling sub-unit, configured to scale a voltage value at afirst input terminal of the comparing unit, to compare the scaledvoltage value with a voltage value at a second input terminal of thecomparing unit.
 10. The touch driving apparatus according to claim 8,wherein, the comparing unit comprises a scaling sub-unit, configured toscale a voltage value at a first input terminal of the comparing unit,to compare the scaled voltage value with a voltage value at a secondinput terminal of the comparing unit.
 11. The touch driving apparatusaccording to claim 5, wherein, the touch driving apparatus comprises atleast one comparing unit in one-to-one correspondence to the at leastone charge sharing bus, each comparing unit has a first terminalconnected with a corresponding charge sharing bus to obtain a busvoltage value, and a second terminal to obtain a reference voltagevalue, so to obtain at least one comparison result, wherein thereference voltage value is associated with a number of output stagecircuits included in the first output stage circuit group and the secondoutput stage circuit group; when a number of comparison resultsindicating that a bus voltage value obtained from a corresponding chargesharing bus and the reference voltage value meet a threshold conditionis greater than or equal to a third preset number, the controllerdetermines that the first time period ends.
 12. The touch drivingapparatus according to claim 2, wherein, each output stage circuitcomprises a first switch and a second switch connected in series betweenthe high-level power supply terminal and the low-level power supplyterminal; and a connection node of the first switch and the secondswitch is connected to an output terminal of the output stage circuit;the controller controls turning off the first switch and the secondswitch of each output stage circuit in the first output stage circuitgroup and the second output stage circuit group within the first timeperiod; and after the first time period, the controller controls turningon the first switch and turning off the second switch of each outputstage circuit in the second output stage circuit group, to utilize powerfrom the high-level power supply terminal to charge the drivingelectrode connected to the output stage circuit via the first switch,and controls turning on the second switch and turning off the firstswitch of each output stage circuit in the first output stage circuitgroup, to release remaining power from the driving electrode connectedto the output stage circuit to the low-level power supply terminal viathe second switch.
 13. The touch driving apparatus according to claim 1,wherein, the controller determines an expected driving signalcorresponding to each driving electrode according to the CDM codematrix, wherein, each expected driving signal comprises a plurality ofdriving time periods, and a duration of each driving time period is halfof the cycle of the driving signal, for each driving time period, thecontroller determines the first output stage circuit group and thesecond output stage circuit group based on the determined expecteddriving signal corresponding to each driving electrode.
 14. The touchdriving apparatus according to claim 1, wherein, there are a pluralityof output modules, and each output module is connected to a drivingelectrode group, and the number of driving electrodes in the drivingelectrode group is equal to the number of output stage circuits includedin the output module.
 15. A touch control apparatus, comprising: a touchpanel, comprising a touch sensor comprising a plurality of drivingelectrodes and a plurality of sensing electrodes intersecting with eachother; the touch driving apparatus according to claim 1, wherein, thetouch driving apparatus is configured to supply driving signals to theplurality of driving electrodes on the touch panel.
 16. A touch drivingmethod used for a touch sensor, wherein, the touch sensor comprises aplurality of driving electrodes and a plurality of sensing electrodesintersecting with each other; the plurality of driving electrodes aredivided into at least one group; each group corresponds to an outputmodule; and each output module comprises output stage circuits whosenumber is equal to that of driving electrodes of each group, the methodcomprises: for each output module, determining a first output stagecircuit group and a second output stage circuit group in the currentdriving time period according to a Code Division Multiple Access (CDM)code matrix, wherein, a first driving signal group at an output terminalof the first output stage circuit group is expected to discharge a firstdriving electrode group, and a second driving signal group at an outputterminal of the second output stage circuit group is expected to chargea second driving electrode group; and controlling utilizing power fromthe first driving electrode group to charge the second driving electrodegroup, in response to the determination.
 17. The touch detecting methodaccording to claim 16, wherein, the controlling utilizing power from thefirst driving electrode group to charge the second driving electrodegroup, comprises: controlling utilizing the power from the first drivingelectrode group to charge the second driving electrode group up to thefirst time period; and after the first time period, controllingreleasing remaining power from the first driving electrode group to alow-level power supply terminal, and utilizing a high-level power supplyterminal to continue to charge the second driving electrode group. 18.The touch detecting method according to claim 16, wherein, at least onepath switch is provided between output terminals of every two outputstage circuits included in each output module, the controlling utilizingthe power from the first driving electrode group to charge the seconddriving electrode group, further comprises: in the first time period,disabling, by the controller, the first output stage circuit group andthe second output stage circuit group, and controlling turning on atleast part of the at least one path switch, so that the power from thefirst driving electrode group charges the second driving electrodegroup; and after the first time period, enabling, by the controller, aconductive path between the output terminal of the first output stagecircuit group and the low-level power supply terminal as well as aconductive path between the high-level power supply terminal and theoutput terminal of the second output stage circuit group, andcontrolling turning off the at least part of the at least one pathswitch.